Sue talked on her cell phone for

irina1246 [14]

Answer:

2.5 hours

Skills needed: Speed, distance, time problems

Step-by-step explanation:

1) We are given speed and distance, and have to find out the the time (in hours).

- In terms of units, everything is matched up (Since distance and speed use kilometers, and speed and time use hours).

- Time is always the distance you travelled (how far) divided by how fast you travelled (the rate/speed)

---> We can use the formula for time: $t=\frac{d}r$

t= time

d=distance

r=rate/speed

2) Now, let's plug in for distance and rate.

---> $t=\frac{7.5}{3} = 2.5$

2.5 hours is the answer.

4 0

3 years ago

Find an equation that models the path of a satellite if its path is a hyperbola, a = 55,000 km, and c= 81,000 km. Assume the cen

elena-14-01-66 [18.8K]

Answer:

$\frac{x^2}{55000^2} - \frac{y^2}{59464^2} =1$

Step-by-step explanation:

the transverse axis is horizontal.

so its a horizontal hyperbola

Center is the origin so center is (0,0)

Equation of horizontal hyperbola is

$\frac{x^2}{a^2} - \frac{y^2}{b^2} =1$

Given a= 55000 and c= 81000

c^2 = a^2 + b^2

81000^2 = 55000^2 + b^2

subtract 55000^2 on both sides

b = sqrt(81000^2 - 55000^2)= 59464.27

now plug in the values

$\frac{x^2}{55000^2} - \frac{y^2}{59464^2} =1$

7 0

3 years ago

Which table shows a proportional relationship and the correct amount of each ingredients

ollegr [7]

I am pretty sure that it is table one because each number from the original recipe to the teachers recipe is multiplied by three.

5 0

3 years ago

Given: PS=RT, PQ=ST Prove: QS=RS

ivanzaharov [21]

Answer:

I) Eq(1) reason: sum of segments of a straight line

II) Eq(2) reason: Given PQ = ST & PS = RT

III) Eq(3) reason: sum of segments of a straight line

IV) Eq(4) reason: Same value on right hand sides of eq(2) and eq(3) demands that we must equate their respective left hand sides

V) Eq(5) reason: Usage of collection of like terms and subtraction provided this equation.

Step-by-step explanation:

We are given that;

PS = RT and that PQ = ST

Now, we want to prove that QS = RS.

From the diagram, we can see that from concept of sum of segments of a straight line we can deduce that;

PQ + QS = PS - - - - (eq 1)

Now, from earlier we saw that PQ = ST & PS = RT

Thus putting ST for PQ & PS for RT in eq 1,we have;

ST + QS = RT - - - - (eq 2)

Again, from the line diagram, we can see that from concept of sum of segments of a straight line we can deduce that;

RS + ST = RT - - - - -(eq 3)

From eq(2) & eq(3) we can see that both left hand sides is equal to RT.

Thus, we can equate both left hand sides with each other to give;

ST + QS = RS + ST - - - (eq 4)

Subtracting ST from both sides gives;

ST - ST + QS = RS + ST - ST

This gives;

QS = RS - - - - (eq 5)

Thus;

QS = RS

Proved

5 0

3 years ago

Find the y-intercept for the parabola defined by the equation y=x^2-x-12

o-na [289]

Answer:

The y-intercept is (0,-12).

Step-by-step explanation:

Given equation is $y=x^2-x-12$ .

Now question says to find the y-intercept of the given parabola $y=x^2-x-12$ .

We know that y-intercept means the y-value when x-value equals 0

so let's plug x=0 into given equation $y=x^2-x-12$ then solve that for y.

$y=x^2-x-12$

$y=0^2-0-12$

$y=0-0-12$

$y=-12$

Hence the y-intercept is (0,-12).

6 0

3 years ago